Pilot Tube : An impact tube, usually a piece of tubing bent 90 degrees and inserted in line with open end facing into flow stream. A flow measurement device. (WT)
The Mudblogger (Oilfield, Energy and Related Photographs), Oil Field Glossary, TX, USA 2014. http://mudblogger.com/oilfield-glossary/, (Oil - Amer) {777}